Dividing device



W. L. GODMAN DIVIDING DEVICE July 5, 1966 2 Sheets-Sheet 1 Filed March 27, 1.964

INVENTOR Warren L. 60097700 BY Malia/0 ATTORNEY W. L. GODMAN DIVIDING DEVICE July 5, 1966 2 Sheets-Sheet 2 Filed March 27, 1964 INVENTOR Warren L. God/nan BY M ATTORNEY United States Patent 3,258,844 DIVIDING DEVICE Warren L. Godman, 6646 Loch Hill Road, Baltimore 12, Md. Filed Mar. 27, 1964, Ser. No. 355,246 4 Claims. (Cl. 33-110) This invention relates generally to geometrical instruments, and more particularly it pertains to a proportional point marker.

In drafting practice, it is usual to lay out equal spaces with a divider compass. The process involves stepping 01f this distance by means of sharp pointed legs. Unless the divider legs are set exactly an accumulated error results and several tries are required before the series of intervals precisely fit the distance being divided.

It is an object of the present invention, therefore, to provide a drafting instrument in the nature of a slide rule in which a precisely divided stick spans the area to be divided and the slider carries the increment whereby each increment placement is referenced against the stick.

A further object of this invention is to provide a detentable slider on a dividing instrument which in conjunction with a stylet and a settable interval pointer considerably reduces the labor and difiiculty of stepping olf spaced intervals.

Other objects and attendant advantages of this invention will become more readily apparent and understood from the following detailed specification and accompanying drawings in which:

FIG. 1 is a perspective depiction of the invention in use;

FIG. 2 is a fragmentary top plan view much enlarged;

FIG. 3 is a fragmentary edge View;

FIG. 4 is an enlarged view of the stylet in an increment marking groove;

FIG. 5 is a sectional view of the adjustable marker and stylet taken on line 5-5 of FIG. 3; and

FIG. 6 is a sectional view of the fastening means for the marker slide taken on line 66 of FIG. 3.

Referring now to the details of the drawings, the novel dividing instrument designated generally by reference numeral 10 consists of a ruled stick assembly 12 and a ruled slide assembly 14 thereon. The sticks assembly 12 comprises a long straight rule 16 and and an equal length but narrower base strip 18. The rule 16 is milled or embossed deeply with equal increment marks 20 for example one-sixteenth A or one-eighth /s) of an inch for its entire length near one edge of the face thereof.

The base strip 18 is mounted underneath by means of flat head fasteners 22 so that it is centered and the edges of the rule 16 project on each side.

The slide assembly 14 is made up of a strip 24 wider than the rule 16 and has an edgewise protruding tongue or jaw 26 formed at one end. The underside of the strip 24 is machined lengthwise with a recess 28 to fit slidably upon the base strip 18. The recess 28 is further undercut on each side to clear the edges of the long rule 16 and .to form captivating flanges 30 as best shown in FIG. 6.

An aperture 32 elongated lengthwise of the slider assembly is cut through the strip 24 so as to expose a length of the increment marks 20 of the long rule. A short rule having increments 36 marked thereon and equal in length to the aperture 32 is mounted on fasteners 38 to the strip 24 adjacent to the aperture 32. Beveled spacers 40 are used to tilt the short rule 34 so the increment marks 36 thereon are as close as possible to the increment marks 20 of the long rule showing through the aperture 32.

As shown in FIGS. 4 and 5, a round rod stylet 50 is provided which is machined to an axial point 42 which best fits the embossed increment marks 20 of the long rule. The ends of the aperture 32 are machined to a radius 44 corresponding to that of the stylet body. Consequently, the point 42 of the stylet 50 will accurately align with the end increments of the short rule 34 when inserted in the aperture 32 and .the slide assembly 14 is at its right or left extreme thereagainst.

One edge of the jaw 26 is machined accurately straight and at right angles to the recess 28 of the strip 24 to form a marking edge 46.

A detent spring 48 is secured by a screw 52 to one end of the strip 24 so as to engage the embossed increment marks 20 of the long rule 16 in a positive manner.

A marker or pointer 54 is fitted to slide on the upper edge of the short rule 34 and when clamped thereon by means of a thumb screw 56 serves to rapidly identify the desired increment being laid out.

In use, the dividing instrument 10 is secured parallel and adjacent to the length which is to be divided into increments. The marker or pointer 54 is clamped to indicate the desired increment on the short rule 34. The slide assembly 14 is moved on the stick assembly 12 so that its marking edge 46 coincides with the beginning of the length to be divided making sure the detent spring 48 engages in one of the increment marks of the long rule 16. Next, the stylet 50 is inserted into the elongated aperture 32 at the indicated desired increment (2% inches in the illustration), with the point 42 thereof engaged with the long rule increment mark 20 thereat.

The slide assembly 14 is then moved in the desired direction until stopped by the end radius 44 against the stylet 50. A mark A is then made against the marking edge 46 up on the work.

The stylet 50 is then lifted and advanced to the indicated increment mark again and held against the embossed increments there-opposite of the long rule 16. The slide assembly 14 is moved up against the stylet as previously related and another mark B is made on the work.

In this manner, the increments are stepped off, a continual reference to the long rule 16 being made by the detent spring 48. Thus perfect spaces will always be obtained and the last space will end exactly on the final point of the length being divided.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A device for marking increments on an object, comprising ruler means having increment positions spaced therealong, strip means slidably mounted on said ruler means and having an aperture for exposing said increment positions to visual observation, first means for engaging with one of said increment positions to form a first reference location for said strip means, a pointer mechanism positioned on staid strip means for indicating a second reference location for said strip means, and second means positioned within said aperture for engaging the increment position corresponding to said second reference location, with said strip means having a marking edge for marking said first and second reference locations on said object.

2. The device as recited in claim 1 wherein said pointer mechanism is slidable along said strip means and means are provided to maintain said pointer mechanism in the position selected.

3. The device as recited in claim 1 and additionally, second ruler means mounted on said strip means along said aperture.

4. The device as recited in claim 1 wherein said first means for engaging is a detent spring secured to said 7 strip.

References Cited by the Examiner UNITED Pratt 33110 Soltmann 3 3-8 1 Cangialosi 331 10 5 ISAAC LISANN, Primary Examiner.

HARRY N. HAROIAN, Assistant Examiner. 

1. A DEVICE FOR MARKING INCREMENTS ON AN OBJECT, COMPRISING RULER MEANS HAVING INCREMENT POSITIONS SPACED THEREALONG, STRIP MEANS SLIDABLY MOUNTED ON SAID RULER MEANS AND HAVING AN APERTURE FOR EXPOSING SAID INCREMENT POSITIONS TO VISUAL OBSERVATION, FIRST MEANS FOR ENGAGING WITH ONE OF SAID INCREMENT POSITIONS TO FORM A FIRST REFERENCE LOCATION FOR SAID STRIP MEANS, A POINTER MECHANISM POSITIONED ON SAID STRIP MEANS FOR INDICATING A SECOND REFERENCE LOCATION FOR SAID STRIP MEANS, AND SECOND MEANS POSITIONED WITHIN SAID APERTURE FOR ENGAGING THE INCREMENT POSITION CORRESPONDING TO SAID SECOND REFERENCE LOCATION, WITH SAID STRIP MEANS HAVING A MARKING EDGE FOR MARKING SAID FIRST AND SECOND REFERENCE LOCATIONS ON SAID OBJECT. 